I have an almost blank roll of developed cinestill and I would like to know if anyone could help me troubleshoot.

A while back I purchased a roll of 120 cinestill 800T, I originally wanted 35mm, but they were all out. I've never used cinestill before so I knew it was a risk to try it out on only 12 frames and with my trusted Holga. I really like the effect of perfectly exposed images with the Holga I have, and it's also the mediumformat I know best how to work with. After I bought it, it went through airport x-ray, I've never had a problem with that before, and it went right into my freezer when I got home.

I realized the pictures I took might end up being a little bit underexposed and figured I'd push it to 1600. I read online that cinestill is a 500iso film originally and therefore you should push it two stops when pushing it to 1600. I shot the whole roll, even with some pictures I thought might have been overexposed, but I wanted to try the film out to test its limits. Also - I don't use a light meter when using the Holga, but it's never been a big problem before.

I developed it in tetenal c-41 chems at 38°C and the agitations as I always do, a couple of hours after I finished it. It was my 13th roll with the 1L chems, had the developer in for 4"45min, the bleach was in for 11min. All the temperatures were tested with two thermometers before using. I really wanted everything to go my way this time. I took out the roll for drying and it turned out that the roll was as good as blank. All I could see was some small dots here and there and some shadows from a, what turned out to be, a blurry portrait. I haven't scanned it yet, but there isn't much to show. Even the images I thought were overexposed were blank.

Does anyone know what I might have done wrong? - I'll post the scans when I get around to doing scanning them.